Study of genetic architecture of grain yield and quality traits through generation mean analysis in rice (Oryza sativa L.)
Abstract
A perusal of gene effects in generation mean analysis for three crosses viz., BPT 5204 x IR 36, BPT 5204 x NLR 34449 and RNR 2465 x IR 64 revealed the presence of a significant proportion of epistatic effects besides the major components viz., additive (d) and dominance (h) gene effects for important yield and quality attributes. Partitioning of variance indicating that the mean values (m) for gene effects were highly significant in all the three crosses for most of the traits, the results of dominance (h) and dominance × dominance (l) type interactions revealed that duplicate type of epistasis was prevalent for most of the traits in all the six crosses except in RNR 2465 x IR 64 for the number of filled grains per panicle; BPT 5204 x NLR 34449 for kernel breadth and kernel elongation ratio and BPT 5204 x IR 36 for harvest index where, complementary gene action played a vital role in the inheritance of the traits. Therefore, improvement of these traits appears to overwhelmed with difficulties as simple selection techniques will not be able to fix superior lines in the early segregating generations. Postponement of selection for superior lines to later generations in pedigree breeding will be effective. However, one or two cycles of recurrent selection followed by pedigree breeding will be effective and useful to utilize both additive and non-additive gene effects. The predominance of dominance and epistatic interactions in all the crosses for quality traits indicates that selection would be more effective if the dominance and epistatic effects are first reduced by a few generations of selfing.
Keywords: Rice, generation mean analysis, gene action
It is certified that:
- The corresponding author is fully responsible for any disputes arising due to the publication of his/her manuscript.
- The article has been seen by all the authors who are satisfied with its form and content.
- The sequence of names of authors in the by-line is as per their relative contribution to this experiment, giving due credit to all scientists who made notable contribution to it.
- All the authors fully understand that inclusion of any other co-authors or exclusion of any co-authors is not possible once the article has been submitted to the journal.
- The corresponding author takes full responsibility for this article.
- The address of the organization where the research was conducted is given.
- The article is exclusive for this journal, and the results reported here have not been sent (and will not be sent during its consideration by this journal) for publication in any other journal.
- Authors agree to abide by the objective comments of referees and do agree to modify the article into a short note as per the recommendation, for publication in the Electronic Journal of Plant Breeding.
- If published in Electronic Journal of Plant Breeding, the copyright of this article would vest with the Indian Society of Plant Breeders, who will have the right to enter into any agreement with any organization in India or abroad engaged in reprography, photocopying, storage and dissemination of information contained in it, and neither we nor our legal heirs will have any claims on royalty.
